Centrifugal fan



' Mar. 6, 1923,

' 1,447,916 J. A. WATKINS CENTR'IFUGAL FAN 2 sheets-sheet 1 Filed Dec. 18, 1920 why 4,

after/c1 65,

vwemtoz Federated Mar; 6, 1923.

a as i "r a JAMES A. WATKINS, F DETROIT, MICHIGAN, ASSIGNOR TO AMERICAN BLOWER,

COMPANY, OF DETROIT, MICHIGAN, A'CORPORATION OF MICHIGAN.

OENTRIFUGAL FAN.

Application filed December 18, 1920. Serial 1H0. 431,591.

To all whom it may concern: I

Be it known that I, JAMES A. WATKINS, a citizen of the United States, residing at Detroit, in the county of Wayne and State 5 of Michigan, have invented certain new and useful Improvements in Centrifugal Fans, of

which the following is a specification, refer ence'being had therein to the accompanying drawing.

This invention relates to improvements in centrifugal fans of the type having an annular peripheral discharge nozzle described in my prior application for centrifugal fan, filed Get. 6, 1920, Serial No. 414,987.

An important novel characteristic of the present invention resides in the provision of a centrifugal fan with an annular peripheral discharge nozzle constructed and arranged to-discharge laterally or axially of the wheel.

The invention, with other objects and advantages thereof, and the particular construction, combination and arrangement of parts comprising the same, will be understood from the hereinafter detailed descrip- 26 tion, when considered in connection with the accompanying drawings forming parthereof and illustrating embodiments of the invention.

In the drawings Figure 1 is a vertical section of a centrifugal fan constructed in accordance with the present invention.

Figure 2 is a side elevation with a one end plate broken away.

Figure 3 is a vertical section of a modified construction.

Figure at is a vertical section illustrating another modification.

part of Referring to Figs. 1 and 2 of the draw- 40 ings, the invention is here shown applied to a fan wheel structure comprising a front coned ring 1 having the opening 2 forming the eye of the fan, a back disk and hub 3, 4, and blades 5, the latter each consisting of an inner radially extending part 5, an intermediate part 5 curved in approximately the segment of a cylinder, and an outer portion 5 extendin in a direction diverging from the plane 0 the inner radial part 5.

The invention comprehends a peripheral nozzle for the fan wheel comprising spaced annular walls formin a continuation of the shrouding or the end plates of the wheel that will afford an opendischarge all around the wheel and give the air sufiicient directive velocity so that less disturbance is caused at the exit of'the blades and providin for a forward or backward discharge axially of the wheel.

' In the particular construction illustrated, by way of example, F igs. 1 and 2, the discharge nozzle is shown combined with the fan wheel asa single part to rotate therewith, the nozzle being formed by annular extensions of the front coned ring 1 and back plate 3. The annular extension of the back plate 3 has an innervconical portion 6 extending at an inward inclination, a conical portion 6 extending at an outward inclination at an angle about equal to the angle of inclination of the part 6, and anouter laterally curved part 6*. The extension of the front coned ring 1 consists of an inner conical part 7 shown extending inwardly at the same angle as that of the conical ring 1, and an outer laterally curved part 7. The inner opposing portions'6, Gig-and 7 of the extensions of the back plate 3 a-nd coned rin 1 form an innernOZZIe pa-rt haWing inwar ly converg ing walls, the outer curved portions 6"- and 7 b having outer outwardly diverging lips or end ortions,6,f7., said curved portions 6 and intermediate the end portions 6, 7,

and the inner wall portions 6 and 7, being spaced from each other a substantially equal as axially extending circumferentially backward discharge. The inner part of the nozzle formed by the opposing wall portions 6, 6 and 7 of the extensionsis shaped to conform to the path of the air as it would leave the wheel under open discharge conditions, thisinner part; of the nozzle simply acting to continue the convergence of the air to such a point as to give it suflicient directive velocity. F rom this point the air passing through the outer outlet art of the nozzle is directed laterally and dlscharged substantially parallel with the axis of the wheel.

The modified construction illustrated in Fig. 3 of-the'drawings is substantially the same as that shown in Figs. 1 and, 2 except that the nozzleisformed as a separate part from-the wheel and has a forward instead of abackward discharge. In'this figure, 8 designates the fan' wheel, 9 the inner part of the nozzle having inwardly converging wall portions-,-and 10 the outer curved wall zle is composed of annular extensions of the end plate portions a, b of the wheel, said extensions having opposing inwardly converging inner port-ions a, 6 and outer por tions a 6 the latter being curved as shown and arranged relative to the wallportion a to provide there-with a discharge substantially axially of the wheel.

The constructions hereinbefore described provide an open .discharge all around the wheel, the diffusion taking place a considerable distance from the wheel structure so that less disturbance is caused at the exit of the blades, resulting in a material increase in efliciency, while at the same time provision is made for either a forward or backward discharge, andthe scroll volute housing commonly employed with centrifugal fans being entirely dispensed with.

I desire it to be understood that the invention, in its broader aspect, is not to .be limited to any special construction of fan wheel; that the same is applicable to the various types of fan wheels, and that variations and changes in the particular nozzle structure illustrated in the drawings, and theembodiment of the invention in other forms as will appeal to those skilled in the art and falling within the scope of the appended claims, may be made without departing from the principles of the invention.

What I claim is 1. A centrifugal fan consisting of an unenclosed fan wheel provided with an annular peripheral discharge noz'zleextending beyond the delivery end portions of the fan blades and rotatable with the fan wheel, said nozzle being constructed and arranged to discharge the air laterally of the wheel.

2. A centrifugal fan consisting of an unenclosed fan wheel provided with an annular peripheral discharge nozzle extending beyond the delivery end portions of the blades and rotatable with the fan wheel, saidnozzle being constructed and arranged todischarge the air circumferentially and substantially parallel to the axis of rotation of the fan wheel.

3. A centrifugal fan consisting of an un enclosed fan wheel provided with anannular peripheral discharge nozzle extending beyond the delivery end portions of the blades and rotatable with the fan wheel, said discharge nozzle being constructed and arg outer coned portion 6', and c Lemme ranged to discharge the air laterally'of the wheel, the nozzle having annular-inwardly converging wall portions.

4. A contrifugal fan including a fan blades and rotatable with the fan Wheel, said nozzle having an inner part provided with annular inwardly converging walls, and an 3 outer laterally extending outlet part.

6. A centrifugal fan consisting of a fan wheel, and an annularperipheral discharge nozzle therefor rotatable therewith, the nozzlehaving a part extending substantially radially of the wheel and provided with in wardly converging walls, and said nozzle tending substantially radially o the wheel and provided with inwardly converging walls, and said-nozzle having au outer outlet part extending substantiall parallel with the axis of rotation of the fan wheel and provided with outwardly diverging wall portions at the outer end thereof.

8. A centrifugal fan consisting of a fan wheel comprising aflat back-disk section disposed at right angles to the axis of the wheel, a front coned ring, blades between the disk and ring, said back-disk section and coned ring being provided withannular pev ripheral extensions rotatable therewith and forming an annular discharge nozzle having a laterally extending outlet part.

9. A centrifugal fan consisting of a fan wheel comprising a fiat back-disk section disposed at right angles to the wheel, a front coned ring, blades between the disk and ring, said back-disk section and coned I ring being provided with annular peripheral laterally extending outlet part.

11. Acentrifugal fan consisting of'a fan wheel comprismg a fiat back-disk section converging walls, and an adjoining curved eanne v disposed at right angles to the axis of the wheel, a front coned ring, blades between the disk and ring, the back-disk section and coned ring having annular peripheral extensions rotatable therewith and forming an annular discharge nozzle, the back disk extension having an inner annular'portion extending at an inward inclination, and the coned ring extension having an inner por- 10 tion extending inwardly at the angle of the coned ring, and said extensions having outer laterally curved portions providing a laterally extending outlet.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

JAMES A. WATKINS.

Witnesses:

FREDERICK R. STILL, EDWIN Bnnnn.' 

